U.S. patent number 9,434,906 [Application Number 13/849,884] was granted by the patent office on 2016-09-06 for marine diesel engine lubricating oil compositions.
This patent grant is currently assigned to Chevron Oronite Company, LLC, Chevron Oronite Technology B.V.. The grantee listed for this patent is Ronald Theodorus Fake Jukes, Eugene E. Spala. Invention is credited to Ronald Theodorus Fake Jukes, Eugene E. Spala.
United States Patent |
9,434,906 |
Jukes , et al. |
September 6, 2016 |
Marine diesel engine lubricating oil compositions
Abstract
Disclosed herein are marine diesel engine lubricating oil
compositions which comprises (a) a major amount of an oil of
lubricating viscosity, and (b) about 3 wt. % to about 40 wt. %,
based on the total weight of the marine diesel engine lubricating
oil composition, of a sulfurized, alkaline earth metal alkylphenate
detergent which is substantially free of polyol promoter oxidation
products.
Inventors: |
Jukes; Ronald Theodorus Fake
(Rotterdam, NL), Spala; Eugene E. (Fairfield,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Jukes; Ronald Theodorus Fake
Spala; Eugene E. |
Rotterdam
Fairfield |
N/A
CA |
NL
US |
|
|
Assignee: |
Chevron Oronite Company, LLC
(San Ramon, CA)
Chevron Oronite Technology B.V. (Rotterclam,
NL)
|
Family
ID: |
51569574 |
Appl.
No.: |
13/849,884 |
Filed: |
March 25, 2013 |
Prior Publication Data
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|
Document
Identifier |
Publication Date |
|
US 20140287969 A1 |
Sep 25, 2014 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M
169/044 (20130101); C10M 159/22 (20130101); C10N
2060/10 (20130101); C10N 2040/252 (20200501); C10N
2070/00 (20130101); C10N 2030/10 (20130101); C10N
2020/02 (20130101); C10M 2219/089 (20130101); C10N
2030/52 (20200501); C10M 2219/046 (20130101); C10M
2207/262 (20130101); C10N 2030/04 (20130101); C10N
2030/02 (20130101); C10M 2203/1006 (20130101); C10N
2010/04 (20130101) |
Current International
Class: |
C10M
159/22 (20060101); C10M 169/04 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 126 010 |
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Aug 2001 |
|
EP |
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1 486 556 |
|
Dec 2004 |
|
EP |
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Other References
Molter "Chemistry and Technology of Lubricants", Blackie Academic
& Prof sional. 2nd Edition. pp. 287-305 (1997). cited by
applicant.
|
Primary Examiner: Oladapo; Taiwo
Attorney, Agent or Firm: M. Carmen & Associates,
PLLC
Claims
What is claimed is:
1. A marine diesel engine lubricating oil composition which
comprises (a) a major amount of an oil of lubricating viscosity,
and (b) about 3 wt. % to 14.19 wt. %, based on the total weight of
the marine diesel engine lubricating oil composition, of a
sulfurized, alkaline earth metal alkylphenate detergent which is
substantially free of polyol promoter oxidation products, the
sulfurized, alkaline earth metal alkylphenate detergent being
prepared by a process comprising (i) contacting an alkylphenol
having at least one alkyl substituent from 6 to 36 carbon atoms
with sulfur, in the presence of a promoter acid selected from the
group of alkanoic acids having 1 through 3 carbon atoms, mixtures
of the alkanoic acids, alkaline earth metal salts of the alkanoic
acids and mixtures thereof, and at least a stoichiometric amount of
a calcium base sufficient to neutralize the alkylphenol and the
promoter at a temperature of from about 130.degree. C. to about
250.degree. C. under reactive conditions in the absence of at
polyol promoter or an alkanol having 1 to 5 carbon atoms for a
sufficient period of time to react essentially all of the sulfur
thereby yielding a calcium sulfurized alkylphenate essentially free
of elemental sulfur; and (ii) contacting the reaction product of
step (i) with carbon dioxide and additional calcium base, if
required, to provide the desired TBN, in the presence of an
alkylene glycol having 2 to 6 carbon atoms under reactive
conditions at a temperature of from about 150.degree. C. to about
260.degree. C., wherein the marine diesel engine lubricating oil
composition has a total base number (TBN) of from about 30 to about
70.
2. The marine diesel engine lubricating oil composition of claim 1,
having a TBN of from about 40 to about 70.
3. The marine diesel engine lubricating oil composition of claim 1,
having a kinematic viscosity at 100.degree. C. of from about 12.5
to about 26.1 centistokes (cSt).
4. The marine diesel engine lubricating oil composition of claim 1,
further comprising one or more alkaline earth metal sulfonates.
5. The marine diesel engine lubricating oil composition of claim 4,
wherein the one or more alkaline earth metal sulfonates are
alkaline earth metal alkylaromatic sulfonates.
6. The marine diesel engine lubricating oil composition of claim 5,
wherein the one or more alkaline earth metal alkylaromatic
sulfonates are low overbased alkaline earth metal alkylaromatic
sulfonates.
7. The marine diesel engine lubricating oil composition of claim 5,
wherein the one or more alkaline earth metal alkylaromatic
sulfonates are high overbased alkaline earth metal alkylaromatic
sulfonates.
8. The marine diesel engine lubricating oil composition of claim 1,
further comprising one or more alkali or alkaline earth metal salts
of an alkyl-substituted hydroxyaromatic carboxylic acid.
9. The marine diesel engine lubricating oil composition of claim 1,
further comprising a marine diesel engine lubricating oil
composition additive selected from the group consisting of an
antioxidant, ashless dispersant, detergent, rust inhibitor,
dehazing agent, demulsifying agent, metal deactivating agent,
friction modifier, pour point depressant, antifoaming agent,
co-solvent, package compatibiliser, corrosion-inhibitor, dyes,
extreme pressure agent and mixtures thereof.
10. A method for improving oxidative stability of a marine diesel
engine lubricating oil composition used in a marine diesel engine,
the method comprising adding about 3 wt. % to 14.19 wt. %, based on
the total weight of the marine diesel engine lubricating oil
composition, of a sulfurized, alkaline earth metal alkylphenate
detergent which is substantially free of polyol promoter oxidation
products to a marine diesel engine lubricating oil composition
comprising a major amount of an oil of lubricating viscosity to
form a marine diesel engine lubricating oil composition having a
TBN of from about 30 to about 70, wherein the sulfurized, alkaline
earth metal alkylphenate detergent is prepared by a process
comprising (i) contacting an alkylphenol having at least one alkyl
substituent from 6 to 36 carbon atoms with sulfur, in the presence
of a promoter acid selected from the group of alkanoic acids having
1 through 3 carbon atoms, mixtures of the alkanoic acids, alkaline
earth metal salts of the alkanoic acids and mixtures thereof, and
at least a stoichiometric amount of a calcium base sufficient to
neutralize the alkylphenol and the promoter at a temperature of
from about 130.degree. C. to about 250.degree. C. under reactive
conditions in the absence of a polyol promoter or an alkanol having
1 to S carbon atoms for a sufficient period of time to react
essentially all of the sulfur thereby yielding a calcium sulfurized
alkylphenate essentially free of elemental sulfur; and (ii)
contacting the reaction product of step (i) with carbon dioxide and
additional calcium base, if required, to provide the desired TBN,
in the presence of an alkylene glycol having 2 to 6 carbon atoms
under reactive conditions at a temperature of from about
150.degree. C. to about 260.degree. C.
11. The method of claim 10, wherein the marine diesel engine
lubricating oil composition has a TBN of from about 40 to about
70.
12. The method of claim 10, wherein the marine diesel engine
lubricating oil composition has a kinematic viscosity at
100.degree. C. of from about 12.5 to about 26.1 cSt.
13. The method of claim 10, wherein the marine diesel engine
lubricating oil composition further comprises one or more alkaline
earth metal sulfonates.
14. The method of claim 13, wherein the one or more alkaline earth
metal sulfonates are alkaline earth metal alkylaromatic
sulfonates.
15. The method of claim 10, wherein the marine diesel engine
lubricating oil composition further comprises one or more alkali or
alkaline earth metal salts of an alkyl-substituted hydroxyaromatic
carboxylic acid.
16. The method of claim 10, wherein the marine diesel engine
lubricating oil composition further comprises a marine diesel
engine lubricating oil composition additive selected from the group
consisting of an antioxidant, ashless dispersant, detergent, rust
inhibitor, dehazing agent, demulsifying agent, metal deactivating
agent, friction modifier, pour point depressant, antifoaming agent,
co-solvent, package compatibiliser, corrosion-inhibitor, dyes,
extreme pressure agent and mixtures thereof.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention generally relates to a marine diesel engine
lubricating oil composition.
2. Description of the Related Art
In the not so distant past, rapidly escalating, energy costs,
particularly those incurred in distilling crude oil and liquid
petroleum, became burdensome to the users of transportation fuels,
such as owners and operators of seagoing ships. In response, those
users have steered their operations away from steam turbine
propulsion units in favor of large marine diesel engines that are
more fuel efficient. Diesel engines may generally be classified as
slow-speed, medium-speed, or high-speed engines, with the
slow-speed variety being used for the largest, deep shaft marine
vessels and certain other industrial applications.
Slow-speed diesel engines are unique in size and method of
operation. The engines themselves are massive, the larger units may
approach 200 tons in weight and an upward of 10 feet in length and
45 feet in height. The output of these engines can reach as high as
100,000 brake horsepower with engine revolutions of 60 to about 200
revolutions per minute. They are typically of crosshead design and
operate on the two-stroke cycle.
Medium-speed engines, on the other hand, typically operate in the
range of about 250 to about 1100 rpm and may operate on either the
four-stroke or the two-stroke cycle. These engines can be of trunk
piston design or occasionally of crosshead design. They typically
operate on residual fuels, just like the slow-speed diesel engines,
but some may also operate on distillate fuels that contain little
or no residue. These engines can also be used for propulsion,
ancillary applications or both on deep-sea vessels.
Slow- and medium-speed diesel engines are also extensively used in
power plant operations. A slow- or medium-speed diesel engine that
operates on the 2-stroke cycle is typically a direct-coupled and
direct-reversing engine of crosshead construction, with a diaphragm
and one or more stuffing boxes separating the power cylinders from
the crankcase to prevent combustion products from entering the
crankcase and mixing with the crankcase oil. The notable complete
separation of the crankcase from the combustion zone has led
persons skilled in the art to lubricate the combustion chamber and
the crankcase with different lubricating oils.
Accordingly, in large diesel engines of the crosshead type used in
marine and heavy stationary applications, the cylinders are
lubricated separately from the other engine components. The
cylinders are lubricated on a total loss basis with the cylinder
oil being injected separately to quills on each cylinder by means
of lubricators positioned around the cylinder liner. Oil is
distributed to the lubricators by means of pumps, which are, in
modern engine designs, actuated to apply the oil directly onto the
rings to reduce wastage of the oil.
The high stresses encountered in these engines and the use of
residual fuels creates the need for lubricants with a high
detergency and neutralizing capability even though the oils are
exposed to thermal and other stresses only for short periods of
time. Residual fuels commonly used in these diesel engines
typically contain significant quantities of sulfur which, in the
combustion process, combine with water to form sulfuric acid, the
presence of which leads to corrosive wear. In particular, in
two-stroke engines for ships, areas around the cylinder liners and
piston rings can be corroded and worn by the acid. Therefore, it is
important for diesel engine lubricating oils to have the ability to
resist such corrosion and wear.
Accordingly, a primary function of marine cylinder lubricants is to
neutralize sulfur-based acidic components of high-sulfur fuel oil
combusted in slow-speed 2-cycle crosshead diesel engines. This
neutralization is accomplished by the inclusion in the marine
cylinder lubricant of basic species such as metallic detergents.
Unfortunately the basicity of the marine cylinder lubricant can be
diminished by oxidation of the marine cylinder lubricant (caused by
the thermal and oxidative stress the lubricant undergoes in the
engine), thus decreasing the lubricant's neutralization ability.
The oxidation can be accelerated if the marine cylinder lubricants
contain oxidation catalysts such as wear metals that are generally
known to be present in the lubricant during engine operation.
Medium-speed trunk piston engines typically operate using various
types and qualities of diesel fuels and heavy fuel oils. These
engines are lubricated with trunk piston engine oils which are
required to have the ability to form a protective layer between
moving surfaces, neutralize acids, and keep contaminants suspended
in the oil. Unfortunately, these properties can be adversely
affected by oxidation of the oil resulting in viscosity increase,
loss of neutralization capacity and loss of detergency.
A need still remains, therefore, for an improved marine diesel
engine lubricating oil composition having oxidative stability.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a
marine diesel engine lubricating oil composition is provided which
comprises (a) a major amount of an oil of lubricating viscosity,
and (b) about 3 wt. % to about 40 wt. %, based on the total weight
of the marine diesel engine lubricating oil composition, of a
sulfurized, alkaline earth metal alkylphenate detergent which is
substantially free of polyol promoter oxidation products, the
sulfurized, alkaline earth metal alkylphenate detergent being
prepared by the process comprising (i) contacting an alkylphenol
having at least one alkyl substituent from 6 to 36 carbon atoms
with sulfur, in the presence of a promoter acid selected from the
group of alkanoic acids having 1 through 3 carbon atoms, mixtures
of the alkanoic acids, alkaline earth metal salts of the alkanoic
acids and mixtures thereof, and at least a stoichiometric amount of
a calcium base sufficient to neutralize the alkylphenol and the
promoter at a temperature of from about 130.degree. C. to about
250.degree. C. under reactive conditions in the absence of a polyol
promoter or an alkanol having 1 to 5 carbon atoms for to sufficient
period of time to react essentially all of the sulfur thereby
yielding a calcium sulfurized alkylphenate essentially free of
elemental sulfur; and (ii) contacting the reaction product of step
(i) with carbon dioxide and additional calcium base, if required,
to provide the desired TBN, in the presence of an alkylene glycol
having 2 to 6 carbon atoms under reactive conditions at a
temperature of from about 150.degree. C. to about 260.degree. C.,
wherein the marine diesel engine lubricating oil composition has a
total base number (TBN) of from about 20 to about 100.
In accordance with a second embodiment of the present invention,
there, is provided a method for improving oxidative stability of a
marine diesel engine lubricating oil composition used in a marine
diesel engine, the method comprising adding about 3 wt. % to about
40 wt. % based on the total weight of the marine diesel engine
lubricating oil composition, of a sulfurized alkaline earth metal
alkylphenate detergent which is substantially free of polyol
promoter oxidation products to a marine diesel engine lubricating
oil composition comprising a major amount of an oil of lubricating
viscosity to form a marine diesel engine lubricating oil
composition having a TBN of from about 20 to about 100, wherein the
sulfurized, alkaline earth metal alkylphenate detergent is prepared
by a process comprising (i) contacting an alkylphenol having at
least one alkyl substituent from 6 to 36 carbon atoms with sulfur,
in the presence of a promoter acid selected from the group of
alkanoic acids having 1 through 3 carbon atoms, mixtures of said
alkanoic acids, alkaline earth metal salts of said alkanoic acids
and mixtures thereof, and at least a stoichiometric amount of a
calcium base sufficient to neutralize the alkylphenol and the
promoter at a temperature of from about 130.degree. C. to about
250.degree. C. under reactive conditions in the absence of a polyol
promoter or an alkanol having 1 to 5 carbon atoms for a sufficient
period of time to react essentially all of the sulfur thereby
yielding a calcium sulfurized alkylphenate essentially free of
elemental sulfur; and (ii) contacting the reaction product of step
(i) with carbon dioxide and additional calcium base, if required,
to provide the desired TBN, in the presence of an alkylene glycol
having 2 to 6 carbon atoms under reactive conditions at temperature
of from about 150.degree. C. to about 260.degree. C.
In accordance with a third embodiment of the present invention, the
use of about 3 wt. % to about 40 wt, %, based on the total weight
of the marine diesel engine lubricating oil composition, of a
sulfurized, alkaline earth metal alkylphenate detergent which is
substantially free of polyol promoter oxidation products for
improving oxidative stability of a marine diesel engine lubricating
oil composition used in a marine diesel engine and having a TBN of
from about 20 to about 100 and comprising a major amount of an oil
of lubricating viscosity, wherein the sulfurized, alkaline earth
metal alkylphenate detergent is prepared by a process comprising
(i) contacting an alkylphenol having at least one alkyl substituent
from 6 to 36 carbon atoms with sulfur, in the presence of a
promoter acid selected from the group of alkanoic acids having 1
through 3 carbon atoms, mixtures of said alkanoic acids, alkaline
earth metal salts of said alkanoic acids and mixtures thereof, and
at least a stoichiometric amount of a calcium base sufficient to
neutralize the alkylphenol and the promoter at a temperature of
from about 130.degree. C. to about 250.degree. C. under reactive
conditions in the absence of a polyol promoter or an alkanol having
1 to 5 carbon atoms thr a sufficient period of tin to react
essentially all of the sulfur thereby yielding a calcium sulfurized
alkylphenate essentially free of elemental sulfur, and (ii)
contacting the reaction product of step (i) with carbon dioxide and
additional calcium base, if required, to provide the desired FUN,
in the presence of an alkylene glycol having 2 to 6 carbon atoms
under reactive conditions at temperature of from about 150.degree.
C. to about 260.degree. C.
The present invention is based on the surprising discovery that a
sulfurized, alkaline earth metal alkylphenate detergent prepared by
the process described herein advantageously improves the oxidative
stability of a marine diesel engine lubricating oil composition
having a TBN of from about 20 to about 100 when employed in an
amount of about 3 wt. % to about 40 wt, %, based on the total
weight of the marine, diesel engine lubricating oil composition as
compared to a sulfurized, alkaline earth metal alkylphenate
detergent prepared by a process which employs a polyol promoter
such as, e.g., alkylene glycol in step (i) of the process disclosed
hereinabove.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definitions
The term "marine diesel engine lubricating oil composition" as used
herein shall be understood to mean a marine cylinder lubricant or a
trunk piston engine oil.
The term "marine cylinder lubricant" as used herein shall be
understood to mean a lubricant used in the cylinder lubrication of
a slow speed or medium speed diesel engine. The marine cylinder
lubricant is fed to the cylinder walls through a number of
injection points. Marine cylinder lubricants are capable of
providing a film between the cylinder liner and the piston rings
and holding partially burned fuel residues in suspension, to
thereby promote engine cleanliness and neutralize acids formed by,
for example, the combustion of sulfur compounds in the fuel.
The term "trunk piston engine oils" are oils used to lubricate both
the crankcase and the cylinders of a trunk piston engine. The term
"trunk piston" refers to the piston skirt or trunk. The trunk
piston transmits the thrust caused by connecting-rod angularity to
the side of the cylinder liner, in the same way as the crosshead
slipper transmits the thrust to the crosshead guide. Trunk piston
engines are generally medium speed (about 250 to about 1000 rpm)
4-stroke compression-ignition (diesel) engines. Accordingly, the
trunk piston engine lubricating oil compositions, and trunk piston
engine oils (TPEO) described herein (collectively "lubricating oil
compositions") can be used fir lubricating any trunk piston engine
or compression-ignited (diesel) marine engine, such as a 4-stroke
trunk piston engine or 4-stroke diesel marine engine.
A "marine residual fuel" refers to a material combustible in large
marine engines which has a carbon residue, as defined in
International Organization for Standardization (ISO) 10370) of at
least 2.5 wt. % at least 5 wt. %, or at least 8 wt. %) (relative to
the total weight of the fuel), a viscosity at 50.degree. C. of
greater than 14.0 cSt, such as the marine residual fuels defined in
the international Organization for Standardization specification
ISO 8217:2005, "Petroleum products--Fuels (class F)--Specifications
of marine fuels," the contents of which are incorporated herein in
their entirety.
The term "Group II metal" or "alkaline earth metal" means calcium,
barium, magnesium, and strontium.
The term "calcium base" refers to a calcium hydroxide, calcium
oxide, calcium alkoxide and the like and mixtures thereof.
The term "lime" refers to calcium hydroxide also known as slaked
lime or hydrated lime.
The term "overbased calcium sulfurized alkylphenate composition"
refers to a composition comprising a small amount of diluent (e.g.,
lubricating oil) and a calcium sulfurized alkylphenate complex
wherein additional alkalinity is provided by a stoichiometric
excess of a calcium oxide, hydroxide or C.sub.1 to C.sub.6 alkoxide
based on the amount required to react with the hydroxide moiety of
the sulfurized alkylphenol.
The term "lower alkanoic acid" refers to alkanoic acids having, 1
through 3 carbon atoms, i.e., formic acid, acetic acid and
propionic acid and mixtures thereof.
The term "alkylphenol" refers to a phenol group having one or more
alkyl substituents at least one of which has a sufficient number of
carbon atoms to impart oil solubility to the resulting phenate
additive.
The term "polyol promoter" refers to a compound having two or more
hydroxy substituents, generally the sorbitol type, for example,
alkylene glycols and also derivatives thereof and functional
equivalents such as polyol ethers and hydroxycarboxylic acids.
The term "Total Base Number" or "TBN" refers to the level of
alkalinity in an oil sample, which indicates the ability of the
composition to continue to neutralize corrosive acids, in
accordance with ASTM Standard No. D2896 or equivalent procedure.
The test measures the change in electrical conductivity, and the
results are expressed as mgKOH/g (the equivalent number of
milligrams of KOH needed to neutralize 1 gram of a product).
Therefore, a high TBN reflects strongly overbased products and, as
a result, a higher base reserve for neutralizing acids.
The term "base oil" as used herein shall be understood to mean a
base stock or blend of base stocks which is a lubricant component
that is produced by a single manufacturer to the same
specifications (independent of feed source or manufacturer's
location); that meets the same manufacturer's specification; and
that is identified by a unique formula, product identification
number, or both.
In one embodiment, a marine diesel engine lubricating oil
composition is provided which comprises (a) a major amount of an
oil of lubricating viscosity and (b) about 3 wt. % to about 40 wt.
%, based on the total weight of the marine diesel engine
lubricating oil composition, of an overbased sulfurized
alkylphenate detergent which is substantially free of polyol
promoter oxidation products, the overbased sulfurized alkylphenate
detergent being prepared by the process comprising (i) contacting
an alkylphenol having at least one alkyl substituent from 6 to 36
carbon atoms with sulfur, in the presence of a promoter acid
selected from the group of alkanoic acids having 1 through 3 carbon
atoms, mixtures of said alkanoic acids, alkaline earth metal salts
of said alkanoic acids and mixtures thereof, and at least a
stoichiometric amount of a calcium base sufficient to neutralize
the alkylphenol and the promoter at a temperature of from about
130.degree. C. to about 250.degree. C. under reactive conditions in
the absence of a polyol promoter or an all having 1 to 5 carbon
atoms for a sufficient period of time to react essentially all of
the sulfur thereby yielding a calcium sulfurized alkylphenate
essentially free of elemental sulfur; and (ii) contacting the
reaction product of step (i) with carbon dioxide and additional
calcium base, if required, to provide the desired TBN, in the
presence of an alkylene glycol having 2 to 6 carbon atoms under
reactive conditions at temperature of from about 150.degree. C. to
about 260.degree. C., wherein the marine diesel engine lubricating
oil composition has a total base number (TBN) of from about 20 to
about 100.
The marine diesel engine lubricating oil compositions of this
invention will have a total base number (TBN) of from about 20 to
about 100. In one embodiment, the marine diesel engine lubricating
oil compositions of this invention can have a TBN of from about 40
to about 100. In one embodiment, the marine diesel engine
lubricating oil compositions of this invention can have a TBN of
from about $0 to about $0. In one embodiment, the marine diesel
engine lubricating oil compositions of this invention can have a
TBN of from about 40 to about 70. In one embodiment, the marine
diesel engine lubricating oil compositions of this invention can
have a TBN of from about 20 to about 60.
The marine diesel engine lubricating oil compositions of this
invention can have a kinematic viscosity ranging from about 12.5 to
about 26.1 centistokes (cSt) at 100.degree. C. The viscosity of the
marine diesel engine lubricating oil compositions can be measured
by any suitable method, e.g., ASTM D445.
The marine diesel engine lubricating oil compositions of the
present invention can be prepared by any method known to a person
of ordinary skill in the art for making marine diesel engine
lubricating oil compositions. The ingredients can be added in any
order and in any manner. Any suitable mixing or dispersing
equipment may be used for blending, mixing or solubilizing the
ingredients. The blending, mixing or solubilizing may be carried
out with a blender, an agitator, a disperser, a mixer (e.g.,
planetary mixers and double planetary mixers), a homogenizer (e.g.,
a Gaulin homogenizer or Ratline homogenizer), a mill (e.g., colloid
mill, ball mill or sand mill) or any other mixing or dispersing
equipment known in the art.
The oil of lubricating viscosity for use in the marine diesel
engine lubricating oil compositions of this invention, also
referred to as a base oil, is typically present in a major amount,
e.g., an amount greater than 50 wt. %, or greater than about 70 wt
based on the total weight of the composition. In one embodiment,
the oil of lubricating viscosity, is present in an amount of from
70 wt. % to about 95 wt. %, based on the total weight of the
composition. In one embodiment, the oil of lubricating viscosity,
is present in an amount of from 70 wt, to about 85 wt. %, based on
the total weight of the composition. The base oil for use herein
can be any presently known or later-discovered oil of lubricating
viscosity used in formulating a marine diesel engine lubricating
oil compositions for any and all such applications. Additionally,
the base oils for use herein can optionally contain viscosity index
improvers, e.g., polymeric alkylmethacrylates; olefinic copolymers,
e.g., an ethylene-propylene copolymer or a styrene-butadiene
copolymer; and the like and mixtures thereof.
As one skilled in the art would readily appreciate, the viscosity
of the base oil is dependent upon the application. Accordingly, the
viscosity of a base oil for use herein will ordinarily range from
about 2 to about 5000 centistokes (cSt) at 100.degree. Centigrade
(C). Generally, individually the base oils used herein will have a
kinematic viscosity range at 100.degree. C. of about 4 cSt to about
35 cSt. The base oil will be selected or blended depending on the
desired end use and the additives in the finished oil to give the
desired grade of oil, e.g., a marine diesel engine lubricating oil
composition having an SAE Viscosity Grade of 30, 40 50, 60 and the
like.
Base stocks may be manufactured using a variety of different
processes including, but not limited to, distillation, solvent
refining, hydrogen processing, oligomerization, esterification, and
rerefining. Rerefined stock shall be substantially free from
materials introduced through manufacturing, contamination, or
previous use.
The base oil of the lubricating oil compositions of this invention
may be any natural or synthetic lubricating base oil. Suitable base
oil includes base stocks obtained by isomerization of synthetic wax
and slack wax, as well, as hydrocracked base stocks produced by
hydrocracking (rather than solvent extracting) the aromatic and
polar components of the crude. Suitable base oils include those in
all API categories I, II, III, IV and V as defined in API
Publication 1509, 16.sup.th Edition, Addendum I, October, 2009.
Group IV base oils are polyalphaolefins (PAD). Group V base oils
include all other base oils not included in Group I, II, III, or
IV. Although Group I and II base oils are preferred for use in this
invention, these base oils may be prepared by combining one or more
of Group I, II, III, IV and V base stocks or base oils.
Useful natural oils include mineral lubricating oils such as, for
example, liquid petroleum oils, solvent-treated or acid-treated
mineral lubricating oils of the paraffinic, naphthenic or mixed
paraffinic-naphthenic types, oils derived from coal or shale,
animal oils, vegetable oils (e.g., rapeseed oils, castor oils and
lard oil), and the like.
Useful synthetic lubricating oils include, but are not limited to,
hydrocarbon oils and halo-substituted hydrocarbon oils such as
polymerized and interpolymerized olefins, e.g., polybutylenes,
polypropylenes, propylene-isobutylene copolymers, chlorinated
polybutylenes, poly(1-hexenes), poly(1-octenes), poly(1-decenes),
and the like and mixtures thereof; alkylbenzenes such as
dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,
di(2-ethylhexyl)-benzenes, and the like; polyphenyls such as
biphenyls, terphenyls, alkylated polyphenyls, and the like;
alkylated diphenyl ethers and alkylated diphenyl sulfides and the
derivative, analogs and homologs thereof and the like.
Other useful synthetic lubricating oils include, but are not
limited to, oils made by polymerizing olefins of less than 5 carbon
atoms such as ethylene, propylene, butylenes, isobutene, pentene,
and mixtures thereof. Methods of preparing such polymer oils are
well known to those skilled in the art.
Additional useful synthetic hydrocarbon oils include liquid
polymers of alpha olefins having the proper viscosity. Especially
useful synthetic hydrocarbon oils are the hydrogenated liquid
oligomers of C.sub.6 to C.sub.12 alpha olefins such as, for
example, 1-decene trimer.
Another class of useful synthetic lubricating oils includes, but is
not limited to, alkylene oxide polymers, i.e., homopolymers,
interpolymers, and derivatives thereof where the terminal hydroxyl
groups have been modified by, for example, esterification or
etherification. These oils are exemplified by the oils prepared
through polymerization of ethylene oxide or propylene oxide, the
alkyl and phenyl ethers of these polyoxyalkylene polymers (e.g.,
methyl poly propylene glycol ether having an average molecular
weight of 1,000, diphenyl ether of polyethylene glycol having a
molecular weight of 500 to 1000, diethyl ether of polypropylene
glycol having a molecular weight of 1,000 to 1,500, etc.) or mono-
and polycarboxylic esters thereof such as, for example, the acetic
esters, mixed C.sub.3 to C.sub.8 fatty acid esters, or the C.sub.13
oxo acid diester of tetraethylene glycol.
Yet another class of useful synthetic lubricating oils include, but
are not limited to, the esters of dicarboxylic acids e.g., phthalic
acid, succinic acid, alkyl succinic acids, alkenyl succinic acids,
maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric
acid, adipic acid, linoleic acid dimer, malonic acids, alkyl
malonic acids, alkenyl malonic acids, etc., with a variety of
alcohols, e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol,
2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether,
propylene glycol, etc. Specific examples of these esters include
dibutyl adipate, di(2-ethylhexyl)sebacate, di-n-hexyl fumarate,
dioctyl sebacate diisooctyl azelate, diisodecyl azelate, dioctyl
phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl
diester of linoleic acid dimer, the complex ester formed by
reacting one mole of sebacic acid with two moles of tetraethylene
glycol and two moles of 2-ethylhexanoic acid and the like.
Esters useful as synthetic oils also include, but are not limited
to, those made from carboxylic acids having from about 5 to about
12 carbon atoms with alcohols, e.g., methanol, ethanol, etc.,
polyols and polyol ethers such as neopentyl trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, and the
like.
Silicon-based oils such as, for example, polyalkyl-, polyaryl-,
polyalkoxy- or polyaryloxy-siloxane oils and silicate oils,
comprise another useful class of synthetic lubricating oils.
Specific examples of these include, but are not limited to,
tetraethyl silicate, tetra-isopropyl silicate, tetra-(2-ethylhexyl)
silicate, tetra-(4-methyl-hexyl)silicate,
tetra-(p-tert-butylphenyl)silicate,
hexyl-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes,
poly(methylphenyl)siloxanes, and the like. Still yet other useful
synthetic lubricating oils include, but are not limited to liquid
esters of phosphorous containing acids, e.g., tricresyl phosphate,
trioctyl phosphate, diethyl ester of decane phosphionic acid, etc.,
polymeric tetrahydrofurans and the like.
The lubricating oil may be derived from unrefined, refined and
rerefined oils, either natural, synthetic or mixtures of two or
more of any of these of the type disclosed hereinabove. Unrefined
oils are those obtained directly from a natural or synthetic source
(e.g., coal, shale, or tar sands bitumen without further
purification or treatment. Examples of unrefined oils include, but
are not limited to, a shale oil obtained directly from retorting
operations, a petroleum oil obtained directly from distillation or
an ester oil obtained directly from an esterification process, each
of which is then used without further treatment. Refined oils are
similar to the unrefined oils except they have been further treated
in one or more purification steps to improve one or more
properties. These purification techniques are known to those of
skill in the art and include, for example, solvent extractions,
secondary distillation, acid or base extraction, filtration,
percolation, hydrotreating, dewaxing, etc. Rerefined oils are
obtained by treating used oils in processes similar to those used
to obtain refined oils. Such rerefined oils are also known as
reclaimed or reprocessed oils and often are additionally processed
by techniques directed to removal of spent additives and oil
breakdown products.
Lubricating oil base stocks derived from the hydroisomerization of
wax may also be used, either alone or in combination with the
aforesaid natural and/or synthetic base stocks. Such wax isomerate
oil is produced by the hydroisomerization of natural or synthetic
waxes or mixtures thereof over a hydroisomerization catalyst.
Natural waxes are typically, the slack waxes recovered by the
solvent dewaxing of mineral oils; synthetic waxes are typically the
wax produced by the Fischer-Tropsch process. Examples of useful
oils of lubricating viscosity include HVI and XHVI basestocks, such
isomerized wax base oils and UCBO (Unconventional Base Oils) base
oils.
The marine diesel engine lubricating oil compositions of the
present invention also contain as component (b) from about 3 wt. %
to about LIU wt. based on the total weight of the marine diesel
engine lubricating oil composition, of an overbased sulfurized
alkylphenate detergent which is substantially free of polyol
promoter oxidation products. In general, the overbased sulfurized
alkylphenate detergent which is substantially free of polyol
promoter oxidation products is obtained by the process comprising
(i) contacting an alkylphenol having at least one alkyl substituent
from 6 to 36 carbon atoms with sulfur, in the presence of a
promoter acid selected from the group of alkanoic acids having 1
through 3 carbon atoms, mixtures of the alkanoic acids, alkaline
earth metal salts of the alkanoic acids and mixtures thereof, and
at least a stoichiometric amount of a calcium base sufficient to
neutralize the alkylphenol and the promoter at a temperature of
from about 130.degree. C. to about 250.degree. C. under reactive
conditions in the absence of a polyol promoter or an alkanol having
1 to 5 carbon atoms for a sufficient period of time to react
essentially all of the sulfur thereby yielding a calcium sulfurized
alkylphenate essentially free of elemental sulfur; and (ii)
contacting the reaction product of step (i) with carbon dioxide and
additional calcium base, if required, to provide the desired TBN,
in the presence of an alkylene glycol having 2 to 6 carbon atoms
under reactive conditions at a temperature of from about
150.degree. C. to about 260.degree. C., see, e.g., U.S. Pat. No.
5,529,705, the contents of which are incorporated by reference
herein.
The process for preparing the sulfurized, alkaline earth metal
alkylphenate detergent can be conveniently conducted by contacting
the desired alkylphenol with sulfur in the presence of a lower
alkanoic acid and calcium base under reactive conditions. If
desired, the alkylphenol can be contacted with sulfur in an inert
compatible liquid hydrocarbon diluent. The reaction can be
conducted under an inert gas, such as nitrogen, in theory the
neutralization can be conducted as a separate step prior to
sulfurization, but it is generally more convenient to conduct the
sulfurization and the neutralization together in a single process
step. Also, in place of the lower alkanoic acid, salts of the
alkanoic acids or mixtures of the acids and salts could also be
used. Where salts or mixtures of salts and acids are used, the salt
is preferably an alkaline earth metal salt such as a calcium salt.
En general, the acids are preferred and the process will be
described below with respect to the use of lower alkanoic acid;
however, it should be appreciated that the teachings are also
applicable to the use of salts and mixtures of salts in place of
all or a portion of the acids.
The combined neutralization and sulfurization reaction is typically
conducted at temperatures in the range of about from about
115.degree. C. to about 250.degree. C. or from about 135.degree. C.
to about 230.degree. C. depending on the particular alkanoic acid
used. Where formic acid is used, a temperature in the range of
about 150.degree. C. to about 200.degree. C. can be used. Where
acetic acid or propionic acid are used, higher reaction
temperatures may be advantageously employed, for example, at
temperatures in the range of about 180.degree. C. to about
250.degree. C. or from about 200.degree. C. to about 235.degree.
C.
If desired, mixtures of two or all three of the lower alkanoic
acids also can be used. For example, mixtures containing about from
about 5 to about 25 wt formic acid and about from about 75 to about
95 wt acetic acid can be used where low or medium overbased
products are desired. Based on one mole of alkylphenol typically,
from about 0.8 to about 3.5, preferably about 1.2 to about 2 moles
of sulfur and about 0.025 to about 2, preferably about 0.1 to about
0.8 moles of lower alkanoic acid are used. Typically, about 0.3 to
about 1 mole preferably, about 0.5 to about 0.8 mole of calcium
base are employed per mole of alkylphenol.
In addition, an amount of calcium base sufficient to neutralize the
lower alkanoic acid is also used. Thus, from about 0.31 to about 2
moles of calcium base are used per mole of alkylphenol including
the base required to neutralize the lower alkanoic acid. If
preferred, lower alkanoic acid to alkylphenol and calcium base to
alkylphenol ratios are used, the total calcium base to alkylphenol
ratio range will be about from about 0.55 to about 1.2 moles of
calcium base per mole of alkylphenol. As one skilled in the art
will readily appreciate, this additional calcium base will not be
required where salts of alkanoic acids are used in place of the
acids.
The reaction may be carried out in a compatible liquid diluent,
such as a low viscosity mineral or synthetic oil. The reaction is
conducted for a sufficient length of time to ensure complete
reaction of the sulfur, e.g., where high TBN products are desired
because the synthesis of such products generally requires using
carbon dioxide together with a polyol promoter. Accordingly, any
unreacted sulfur remaining in the reaction mixture will catalyze
the formation of deleterious oxidation products of the polyol
promoter during the overbasing step.
Where the neutralization is conducted as a separate step, both the
neutralization and the subsequent sulfurization are conducted under
the same conditions as set forth above. In either case, it is
desirable to remove water generated by the neutralization of the
alkylphenol. This is conventional and generally is accomplished by
continuous distillation during the neutralization. Conveniently, a
high molecular weight alkanol having 8 to 16 carbon atoms may be
added to the neutralization-sulfurization step and/or the
overbasing step as a solvent and also to assist in the removal of
water by forming a water-azeotrope which may then be distilled
off.
Optionally specialized sulfurization catalysts such as those
described in U.S. Pat. No. 4,744,921, the disclosure of which is
hereby incorporated in its entirety, can be employed in the
neutralization-sulfurization reaction together with the lower
alkanoic acid. However, any benefit afforded by the sulfurization
catalyst, for example, reduced reaction time, is offset by the
increase in costs incurred by the catalyst and/or the presence of
undesired residues in the case of halide catalysts or alkali metal
sulfides; especially, as excellent reaction rates can be obtained
by merely using acetic and/or propionic acid and increasing
reaction temperatures.
If a high TBN product is desired, the sulfurized alkylphenate
reaction product can be overbased by carbonation. Such carbonation
can be conveniently effected by addition of a polyol promoter, such
as an alkylene diol, e.g., ethylene glycol, and carbon dioxide to
the sulfurized alkylphenate reaction product. Additional calcium
base can be added at this time and/or excess calcium base can be
used in the neutralization step. In one embodiment, an alkenyl
succinimide or a neutral or overbased Group II metal
hydrocarbylsulfonate is added to either the
neutralization-sulfurization reaction mixture or overbasing
reaction mixture. The succinimide or sulfonate assists in
solubilizing both the alkylphenol and the phenate reaction product
and therefore, when used, may be added to the initial reaction
mixture.
Overbasing is typically conducted at temperatures in the range of
above from about 160.degree. C. to about 190.degree. C. or from
about 170.degree. C. to about 180.degree. C. for about 0.1 to about
4 hours, depending on whether a medium or high TBN product is
desired. Conveniently, the reaction is conducted by the simple
expedient of bubbling gaseous carbon dioxide through the reaction
mixture. Excess diluent and any water formed during the overbasing
reaction can be conveniently removed by distillation either during
or after the reaction.
Carbon dioxide is employed in the reaction system in conjunction
with the calcium base to form the overbased product and is
typically employed at a ratio of about from about 0.5 to about 2
moles per mole of alkylphenol, or from about 0.75 to about 1.5
moles per mole of alkylphenol. The amount of CO.sub.2 incorporated
into the calcium overbased sulfurized alkylphenate provides for a
CO.sub.2 to calcium weight ratio of about from about 0.55 to about
0.7. All of the calcium base including the excess used for
overbasing may be added in the neutralization or a portion of the
Group II base can be added prior to carbonation.
Where a medium TBN product (a TBN of about 150 to 225) is desired,
a stoichiometric amount or slight excess of calcium base can be
used in the neutralization step; for example, about 0.5 to about
1.3 moles of base per mole of alkylphenol in addition to the amount
needed to neutralize the lower alkanoic acid. High TBN products are
typically prepared by using a mole ratio of calcium base to
alkylphenol of about 1 to about 2.5 or about 1.5 to about 2; a
carbon dioxide mole ratio of about 0.5 to about 2 or from about
0.75 to about 1.5 moles of carbon dioxide per mole of alkylphenol
and about 0.5 to about 2.5, or about 1.2 to about 2 moles of
alkylene glycol. Again where lower alkanoic acids are used, in
contrast to their salts, an additional amount of calcium salt
sufficient to neutralize the lower alkanoic acid should be
used.
As noted above all of the excess calcium base needed to produce a
high TBN product can be added in the neutralization-sulfurization
step or the excess above, that needed to neutralize the alkylphenol
can be added in the overbasing step or divided in any proportion
between the two steps. Typically, where very high TBN products are
desired, a portion of the calcium base will be added in the
overbasing step. The neutralization reaction mixture or overbasing
reaction mixture may also contain about 1 to about 20, or about 5
to about 15 weight percent of a neutral or overbased sulfonate
and/or an alkenyl succinimide based on the weight of alkylphenol.
(In general where high TBN are desired, TBN in the range of about
from 250 to 300 are preferred.)
Typically, the process is conducted under vacuum up to a slight
pressure, i.e., pressures ranging from about 25 mm Hg absolute to
about 850 mm Hg absolute or is conducted under vacuum to reduce
foaming up to atmospheric pressure, e.g., about from about 40 mm Hg
absolute to about 760 mm Hg absolute.
Additional details regarding the general preparation of sulfurized
phenates can be found in, for example, U.S. Pat. Nos. 2,680,096;
3,178,368 and 3,801,507, the contents of which are incorporated
herein by reference.
Considering now in detail, the reactants and reagents used in the
present process, first all allotropic forms of sulfur can be used.
The sulfur can be employed either as molten sulfur or as solid
(e.g., powder or particulate) or as a solid suspension in a
compatible hydrocarbon liquid.
It is desirable to use calcium hydroxide as the calcium base
because of its handling convenience versus, for example, calcium
oxide, and also because it affords excellent results. Other calcium
bases can also be used for example, calcium alkoxides.
Suitable alkylphenols which can be used are those wherein the alkyl
substituents contain a sufficient number of carbon atoms to render
the resulting overbased sulfurized calcium alkylphenate composition
oil-soluble. Oil solubility may be provided by a single long chain
alkyl substitute or by a combination of alkyl substituents.
Typically, the alkylphenol used in the present process will be a
mixture of different alkylphenols, e.g., C.sub.20 to C.sub.24
alkylphenol. Where phenate products having a TBN of 275 or less are
desired, it is economically advantageous to use 100% polypropenyl
substituted phenol because of its commercial availability and
generally lower costs. Where higher TBN phenate products desired,
about 25 to about 100 mole percent of the alkylphenol can have
straight-chain alkyl substituent of from about 15 to about 35
carbon atoms and from about 75 to about 0 mole percent in which the
alkyl group is polypropenyl of from 9 to 18 carbon atoms. In one
embodiment, about 35 to about 100 mole percent of the alkylphenol,
the alkyl group will be a straight-chain alkyl of about 15 to about
35 carbon atoms and about from about 65 to 0 mole percent of the
alkylphenol, the alkyl group will be polypropenyl of from about 9
to about 18 carbon atoms. The use of an increasing amount of
predominantly straight chain alkylphenols results in high TBN
products generally characterized by lower viscosities. On the other
hand, while polypropenylphenols are generally more economical than
predominantly straight chain alkylphenols, the use of greater than
about 75 mole percent polypropenylphenol in the preparation of
calcium overbased sulfurized alkylphenate compositions generally
results in products of undesirably high viscosities. However, use
of a mixture of from about 75 mole percent or less of
polypropenylphenol of from about 9 to about 18 carbon atoms and
from about 25 mole percent or more of predominantly straight chain
alkylphenol of from about 15 to about 35 Carbon atoms allows for
more economical products of acceptable viscosities.
The alkylphenols can be para-alkylphenates or ortho alkylphenols.
Since it is believed that p-alkylphenols facilitate the preparation
of highly overbased calcium sulfurized alkylphenate where overbased
products are desired, the alkylphenol is preferably predominantly a
para alkylphenol with no more than about 45 mole percent of the
alkylphenol being ortho alkylphenols; and more preferably no more
than about 35 mole percent of the alkylphenol is ortho alkylphenol.
Alkyl-hydroxy toluenes or xylenes, and other alkyl phenols having
one or more alkyl substituents in addition to at least one long
chained alkyl substituent can also be used.
In general, the selection of alkylphenols can be based on the
properties desired for the marine diesel engine lubricating oil
compositions, notably TBN, and oil solubility. For example, in the
case of alkylphenate having substantially straight chain alkyl
substituents, the viscosity of the alkylphenate composition can be
influenced by the position of an attachment on alkyl chain to the
phenyl ring, e.g., end attachment versus middle attachment.
Additional information regarding this and the selection and
preparation of suitable alkylphenols can be found, for example, in
U.S. Pat. Nos. 5,024,773, 5,320,763; 5,318,710, and 5,320,762, each
of which are incorporated herein by reference.
If a supplemental sulfurization catalyst is employed, it is
typically employed at from about 0.5 to about 10 wt. % relative to
the alkylphenol in the reaction system or from about 1 to about 2
wt. %. In one embodiment, the sulfurization catalyst is added to
the reaction mixture as a liquid. This can be accomplished by
dissolving the sulfurization catalyst in molten sulfur or in the
alkylphenol as a premix to the reaction.
The overbasing procedure used to prepare a high TBN overbased
sulfurized calcium alkylphenate composition can also employ a
polyol promoter, typically a C.sub.2 to C.sub.4 alkylene glycol,
such as ethylene glycol in the overbasing step.
Suitable high molecular weight alkanol which can be used in the
neutralization-sulfurization and overbasing are those containing 8
to 16, or 9 to 15, carbon atoms. When employed, the alkanol is
typically employed at a molar charge of from about 0.5 to about 5
moles or from about 0.5 to about 4 moles or from about 1 to about 2
moles of high molecular alkanol per mole of alkylphenol. Examples
of suitable alkanols include 1-octanol, 1-decanol (decyl alcohol),
2-ethyl-hexanol, and the like. It can be beneficial to use a high
molecular weight alcohol in the process because it acts as a
solvent and also forms an azeotrope with water and hence
facilitates affords a convenient way to remove the water generated
by the neutralization or any other water in the system, by
azeotropic distillation either after or preferably during the
reaction. The high molecular weight alcohol may also play some pan
in the chemical reaction mechanism in the sense that it facilitates
the removal of the byproduct water during the reaction, thus
pushing the reaction to the right of the reaction equation.
In the general preparation of overbased calcium sulfurized
alkylphenates, demulsifiers can be added to enhance the hydrolytic
stability of the overbased sulfurized calcium alkylphenate and may
be similarly employed in the present process if desired. Suitable
demulsifiers which can be used include, by way of example, nonionic
detergents. When used, demulsifiers are generally added at from
about 0.1 to about 1 wt. % to the alkylphenol.
The marine diesel engine lubricating oil compositions of the
present invention may also contain conventional marine diesel
engine lubricating oil composition additives for imparting
auxiliary functions to give a marine, diesel engine lubricating oil
composition in which these additives are dispersed or dissolved.
For example, the marine diesel engine lubricating oil compositions
can be blended with antioxidants, ashless dispersants, detergents
other than the sulfurized, alkaline earth metal alkylphenate
detergent component (b), antiwear agents, rust inhibitors, dehazing
agents, demulsifying agents, metal deactivating agents, friction
modifiers, pour point depressants, antifoaming agents, co-solvents,
package compatibilisers, corrosion-inhibitors, dyes, extreme
pressure agents and the like and mixtures thereof. A variety of the
additives are known and commercially available. These additives, or
their analogous compounds, can be employed for the preparation of
the marine diesel engine lubricating oil compositions of the
invention by the usual blending procedures.
In one embodiment, the marine diesel engine lubricating oil
compositions of the present invention contain essentially no
thickener (i.e., a viscosity index improver).
Examples of antioxidants include, but are not limited to, aminic
types, e.g., diphenylamine, phenyl-alpha-napthyl-amine
N,N-di(alkylphenyl) amines and alkylated phenylene-diamines;
phenolics such as, for example, BHT, sterically hindered alkyl
phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol
and 2,6-di-tert-butyl-4-(2-octyl-3-propanoic) phenol; and mixtures
thereof.
The ashless dispersant compounds employed in the marine diesel
engine lubricating oil compositions of the present invention are
generally used to maintain in suspension insoluble materials
resulting from oxidation during use thus preventing sludge
flocculation and precipitation or deposition on metal parts.
Dispersants may also function to reduce changes in lubricating, oil
viscosity by preventing the growth of large contaminant particles
in the lubricant. The dispersant employed in the present invention
may be any suitable ashless dispersant or mixture of multiple
ashless dispersants for use in a marine diesel engine lubricating
oil composition. An ashless dispersant generally comprises an oil
soluble polymeric hydrocarbon backbone having functional groups
that are capable of associating with particles to be dispersed.
In one embodiment, an ashless dispersant is one or more basic
nitrogen-containing ashless dispersants. Nitrogen-containing basic
ashless (metal-free) dispersants contribute to the base number or
BN (as can be measured by ASTM D 2896) of a lubricating oil
composition to which they are added, without introducing additional
sulfated ash. Basic nitrogen-containing ashless dispersants useful
in this invention include hydrocarbyl succinimides; hydrocarbyl
succinamides; mixed ester/amides of hydrocarbyl-substituted
succinic acids formed by reacting a hydrocarbyl-substituted
succinic acylating agent stepwise or with a mixture of alcohols and
amines, and/or with amino alcohols; Mannich condensation products
of hydrocarbyl-substituted phenols, formaldehyde and polyamines;
and amine dispersants formed by reacting high molecular weight
aliphatic or alicyclic halides with amines, such as polyalkylene
polyamines. Mixtures of such dispersants can also be used.
Representative examples of ashless dispersants include, but are not
limited to, amines, alcohols, amides, or ester polar moieties
attached to the polymer backbones via bridging groups. An ashless
dispersant of the present invention may be, for example, selected
from oil soluble salts, esters, amino-esters, amides, imides, and
oxazolines of long cha hydrocarbon substituted mono and
dicarboxylic acids or their anhydrides; thiocarboxylate derivatives
of long chain hydrocarbons, long chain aliphatic hydrocarbons
having a polyamine attached directly thereto; and Mannich
condensation products formed by condensing a long chain substituted
phenol with formaldehyde and polyalkylene polyamine.
Carboxylic dispersants are reaction products of carboxylic
acylating agents (acids, anhydrides, esters, etc.) comprising at
least about 34 and preferably at least about 54 carbon atoms with
nitrogen containing compounds (such as amines), organic hydroxy
compounds (such as aliphatic compounds including monohydric and
polyhydric alcohols, or aromatic compounds including phenols and
naphthols), and/or basic inorganic materials. These reaction
products include imides, amides, and esters.
Succinimide dispersants are a type of carboxylic dispersant. They
are produced by reacting hydrocarbyl-substituted succinic acylating
agent with organic hydroxy compounds, or with amines comprising at
least one hydrogen atom attached to a nitrogen atom, or with a
mixture of the hydroxy compounds and amines. The term "succinic
acylating agent" refers to a hydrocarbon-substituted succinic acid
or a succinic acid-producing compound, the latter encompasses the
acid itself. Such materials typically include
hydrocarbyl-substituted succinic acids, anhydrides, esters
(including half esters) and halides.
Succinic-based dispersants have a wide variety of chemical
structures. One class of succinic-based dispersants may be
represented by the formula:
##STR00001## wherein each R.sup.1 is independently a hydrocarbyl
group, such as a polyolefin-derived group. Typically the
hydrocarbyl group is an alkyl group, such as a polyisobutyl group.
Alternatively expressed, the R.sup.1 groups can contain about 40 to
about 500 carbon atoms, and these atoms may be present in aliphatic
forms. R.sup.2 is an alkylene group, commonly an ethylene
(C.sub.2H.sub.4) group. Examples of succinimide dispersants include
those described in for example, U.S. Pat. Nos. 3,172,892, 4,234,435
and 6,165,715.
The polyalkenes from which the substituent groups are derived are
typically homopolymers and interpolymers of polymerizable olefin
monomers of 2 to about 16 carbon atoms, and usually 2 to 6 carbon
atoms. The amines which are reacted with the succinic acylating
agents to form the carboxylic dispersant composition can be
monoamines or polyamines.
Succinimide dispersants are referred to as such since they normally
contain nitrogen largely in the form of imide functionality,
although the amide functionality may be in the form of amine salts,
amides, imidazolines as well as mixtures thereof. To prepare a
succinimide dispersant, one or more succinic acid-producing
compounds and one or more amines are heated and typically water is
removed, optionally in the presence of a substantially inert
organic liquid solvent/diluent. The reaction temperature can range
from about 80.degree. C. up to the decomposition temperature of the
mixture or the product, which typically falls between about
100.degree. C. to about 300.degree. C. Additional details and
examples of procedures for preparing the succinimide dispersants of
the present invention include those described in, for example, U.S.
Pat. Nos. 3,172,892, 3,219,666, 3,272,746, 4,234,435, 6,165,235 and
6,440,905.
Suitable ashless dispersants may also include amine dispersants,
which are reaction products of relatively high molecular weight
aliphatic halides and amines, preferably polyalkylene polyamines.
Examples of such amine dispersants include those described in, for
example, U.S. Pat. Nos. 3,275,554, 3,438,757, 3,454,555 and
3,565,804.
Suitable ashless dispersants may further include "Mannich
dispersants," which are reaction products of alkyl phenols in which
the alkyl group contains at least about 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines). Examples of such dispersants include
those described in, for example, U.S. Pat. Nos. 3,036,003,
3,586.629, 3,591,598 and 3,980,569.
Suitable ashless dispersants may also be post-treated ashless
dispersants such as post-treated succinimides, e.g., post-treatment
processes involving borate or ethylene carbonate as disclosed in,
for example, U.S. Pat. Nos. 4,612,132 and 4,746,446; and the like
as well as other post-treatment processes. The carbonate-treated
alkenyl succinimide is a polybutene succinimide derived from
polybutenes having a molecular weight of about 450 to about 3000,
preferably from about 900 to about 2500, more preferably from about
1300 to about 2400 and most preferably from about 2000 to about
2400, as well a mixtures of these molecular weights. Preferably, it
is prepared by reacting under reactive conditions, is mixture of a
polybutene succinic acid derivative, an unsaturated acidic reagent
copolymer of an unsaturated acidic reagent and art olefin, and a
polyamine, such as disclosed in U.S. Pat. No. 5,716,912, the
contents of which are incorporated herein by reference.
Suitable ashless dispersants may also be polymeric, which are
interpolymers of oil-solubilizing monomers such as decyl
methacrylate, vinyl decyl ether and high molecular weight olefins
with monomers containing polar substitutes. Examples of polymeric
dispersants include those described in, for example, U.S. Pat. Nos.
3,329,658; 3,449,250 and 3,666,730.
In one preferred embodiment of the present invention, an ashless
dispersant for use in the mat me diesel engine lubricating oil
composition is a bis-succinimide derived from a polyisobutenyl
group having a number average molecular weight of about 700 to
about 2300. The dispersant(s) for use in the lubricating oil
compositions of the present invention are preferably non-polymeric
(e.g., are mono- or bis-succinimides).
Metal-containing or ash-forming detergents function as both
detergents to reduce or remove deposits and as acid neutralizers or
rust inhibitors, thereby reducing wear and corrosion and extending
engine life. Detergents generally comprise a polar head with a long
hydrophobic tail. The polar head comprises a metal salt of an
acidic organic compound. The salts may contain a substantially
stoichiometric amount of the metal in which case they are usually
described as normal or neutral salts, and would typically have a
total base number or TBN (as can be measured by ASTM D2896) of from
0 to about 80. A large amount of a metal base may be incorporated
by reacting excess metal compound (e.g., art oxide or hydroxide)
with an acidic gas (e.g., carbon dioxide). The resulting overbased
detergent comprises neutralized detergent as the outer layer of a
metal base (e.g., carbonate) micelle. Such overbased detergents may
have a TBN of about 100 or greater, and typically will have a TBN
of from about 250 to about 450 or more.
Representative examples of metal detergents other than the
sulfurized alkaline earth metal alkylphenate detergent component
(b) that can be included in the marine diesel engine lubricating
oil composition of the present invention include sulfonates,
hydroxyaromatic carboxylic acids, phosphonates, and phosphinates.
Commercial products are generally referred to as neutral or
overbased. Overbased metal detergents are generally produced by
carbonating a mixture of hydrocarbons, detergent acid, for example:
sulfonic acid, carboxylate etc., metal oxide or hydroxides (for
example calcium oxide or calcium hydroxide) and promoters such as
xylene, methanol and water. For example, for preparing an overbased
calcium sulfonate, in carbonation, the calcium oxide or hydroxide
reacts with the gaseous carbon dioxide to form calcium carbonate.
The sulfonic acid is neutralized with an excess of CaO or
Ca(OH).sub.2, to form the sulfonate.
In one embodiment, the detergent can be one or more alkali or
alkaline earth metal salts of an alkyl-substituted hydroxyaromatic
carboxylic acid. Suitable hydroxyaromatic compounds include
mononuclear monohydroxy and polyhydroxy aromatic hydrocarbons
having 1 to 4, and preferably 1 to 3, hydroxyl groups. Suitable
hydroxyaromatic compounds include phenol, catechol, resorcinol,
hydroquinone, pyrogallol, cresol, and the like. The preferred
hydroxyaromatic compound is phenol.
The alkyl substituted moiety of the alkali or alkaline earth metal
salt of an alkyl-substituted hydroxyaromatic carboxylic acid is
derived from an alpha olefin having from about 10 to about 80
carbon atoms. The olefins employed may be linear, isomerized
linear, branched or partially branched linear. The olefin may be a
mixture of linear olefins, a mixture of isomerized linear olefins,
a mixture of branched olefins, a mixture of partially branched
linear or a mixture of any of the foregoing.
In one embodiment, the mixture of linear olefins that may be used
is a mixture of normal alpha olefins selected from olefins having
from about 12 to about 30 carbon atoms per molecule. In one
embodiment, the normal alpha olefins are isomerized using at least
one of a solid, or liquid catalyst.
In another embodiment, the olefins are a branched olefinic
propylene oligomer or mixture thereof having from about 20 to about
80 carbon atoms, i.e., branched chain olefins derived from the
polymerization of propylene. The olefins may also be substituted
with other functional groups, such as hydroxy groups, carboxylic
acid groups, heteroatoms, and the like. In one embodiment, the
branched olefinic propylene oligomer or mixtures thereof have from
about 20 to about 60 carbon atoms. In one embodiment, the branched
olefinic propylene oligomer or mixtures thereof have from about 20
to about 40 carbon atoms.
In one embodiment, at least about 75 mole (e.g., at least about 80
mole %, at least about 85 mole %, at least about 90 mole %, at
least about 95 mole %, or at least about 99 mole %) of the alkyl
groups contained within the alkali or alkaline earth metal salt of
an alkyl-substituted hydroxyaromatic carboxylic acid such as the
alkyl groups of an alkaline earth metal salt of an
alkyl-substituted hydroxybenzoic acid detergent are a C.sub.20 or
higher. In another embodiment, the alkali or alkaline earth metal
salt of an alkyl-substituted hydroxyaromatic carboxylic acid is an
alkali or alkaline earth metal salt of an alkyl-substituted
hydroxybenzoic acid that is derived from an alkyl-substituted
hydroxybenzoic acid in which the alkyl groups are the residue of
normal alpha-olefins containing at least 75 mole % C.sub.20 or
higher normal alpha-olefins.
In another embodiment, at least about 50 mole % (e.g., at least
about 60 mole %, at least about 70 mole %, at least about 80 mole
%, at least about 85 mole at least about 90 mole %, at least about
95 mole %, or at least about 99 mole % of the alkyl groups
contained within the alkali or alkaline earth metal salt of an
alkyl-substituted hydroxyaromatic carboxylic acid such as the alkyl
groups of an alkali or alkaline earth metal salt of an
alkyl-substituted hydroxybenzoic acid are about C.sub.14 to about
C.sub.18.
The resulting alkali or alkaline earth metal salt of an
alkyl-substituted hydroxyaromatic carboxylic acid will be a mixture
of ortho and para isomers. In one embodiment, the product will
contain about 1 to 99% ortho isomer and 99 to 1% para isomer. In
another embodiment, the product will contain about 5 to 70% mho and
95 to 30% para isomer.
The alkali or alkaline earth metal salts of an alkyl-substituted
hydroxyaromatic carboxylic acid can be neutral or overbased.
Generally, an overbased alkali or alkaline earth metal salt of an
alkyl-substituted hydroxyaromatic carboxylic acid is one in which
the BN of the alkali or alkaline earth metal salts of an
alkyl-substituted hydroxyaromatic carboxylic acid has been
increased by a process such as the addition of a base source e.g.,
lime) and an acidic overbasing compound (e.g., carbon dioxide).
Sulfonates may be prepared from sulfonic acids which are typically
obtained by the sulfonation of alkyl substituted aromatic
hydrocarbons such as those obtained from the fractionation of
petroleum or by the alkylation of aromatic hydrocarbons. Examples
include those obtained by alkylating benzene, toluene, xylene,
naphthalene, diphenyl or their halogen derivatives. The alkylation
may be carried out in the presence of a catalyst with alkylating
agents having from about 3 to more than 70 carbon atoms. The
alkaryl sulfonates usually contain from about 9 to about 80 or more
carbon atoms, preferably from about 16 to about 60 carbon atoms per
alkyl substituted aromatic moiety.
The oil soluble sulfonates or alkaryl sulfonic acids may be
neutralized with oxides, hydroxides, alkoxides, carbonates,
carboxylate, sulfides hydrosulfides, nitrates, borates and ethers
of the metal. The amount of metal compound is chosen having regard
to the desired TBN of the final product but typically ranges from
about 100 to about 220 wt. % (preferably at least about 125 wt. %)
of that stoichiometrically required.
Overbased detergents may be low overbased. e.g., an overbased salt
having a BN below about 100. In one embodiment, the BN of a low
overbased salt may be from about 5 to about 50. In another
embodiment, the BN of a low overbased salt may be from about 10 to
about 30. In yet another embodiment, the BN of a low overbased salt
may be from about 15 to about 20.
Overbased detergents may be medium overbased, e.g., an overbased
salt having a BN from about 100 to about 250, in one embodiment,
the BN of a medium overbased salt may be from about 100 to about
200. In another embodiment, the BN of a medium overbased salt may
be from about 125 to about 175.
Overbased detergents may be high overbased, e.g., an overbased salt
having a BN above about 250. In one embodiment, the BN of a high
overbased salt may be from about 250 to about 450.
Examples of rust inhibitors include, but are not limited to,
nonionic polyoxyalkylene agents, e.g., polyoxyethylene lauryl
ether, polyoxyethylene higher alcohol ether, polyoxyethylene
nonylphenyl ether, polyoxyethylene octylphenyl ether,
polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether,
polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol
monooleate, and polyethylene glycol monooleate; stearic acid and
other fatty acids; dicarboxylic acids; metal soaps; fatty acid
amine salts; metal salts of heavy sulfonic acid; partial carboxylic
acid ester of polyhydric alcohol; phosphoric esters; (short-chain)
alkenyl succinic acids; partial esters thereof and
nitrogen-containing derivatives thereof; synthetic
alkarylsulfonates, e.g., metal dinonylnaphthalene sulfonates; and
the like and mixtures thereof.
Examples of friction modifiers include, but are not limited to,
alkoxylated fatty amines; borated fatty epoxides; fatty phosphites,
fatty epoxides, fatty amines, borated alkoxylated fatty amines,
metal salts of limy acids, fatty acid amides, glycerol esters,
borated glycerol esters; and fatty imidazolines as disclosed in
U.S. Pat. No. 6,372,696, the contents of which are incorporated by
reference herein; friction modifiers obtained from a reaction
product of a C.sub.4 to C.sub.75, preferably a C.sub.6 to C.sub.24,
and most preferably a C.sub.6 to C.sub.20, limy acid ester and a
nitrogen-containing compound selected from the group consisting of
ammonia, and an alkanolamine and the like and mixtures thereof.
Examples of antiwear agents include, but are not limited to, zinc
dialkyldithiophosphates and zinc diaryldithiophosphates, e.g.,
those described in an article by Born et al. entitled "Relationship
between Chemical Structure and Effectiveness of Some Metallic
Dialkyl- and Diaryl-dithiophosphates in Different Lubricated
Mechanisms", appearing in Lubrication Science 4-2 Jan. 1992, see
for example pages 97-100; aryl phosphates and phosphites,
sulfur-containing esters, phosphosulfur compounds, metal or
ash-free dithiocarbamates, xanthates, alkyl sulfides and the like
and mixtures thereof.
Examples of antifoaming agents include, but are not limited to,
polymers of alkyl methacrylate; polymers of dimethylsilicone and
the like and mixtures thereof.
Examples of a pour point depressant include, but are not limited
to, polymethacrylates, alkyl acrylate polymers, alkyl methacrylate
polymers, di(tetra-paraffin phenol)phthalate, condensates of
tetra-paraffin phenol, condensates of a chlorinated paraffin with
naphthalene and combinations thereof. En one embodiment, a pour
point depressant comprises an ethylene-vinyl acetate copolymer, a
condensate of chlorinated paraffin and phenol, polyalkyl styrene
and the like and combinations thereof. The amount of the pour point
depressant may vary from about 0.01 wt. % to about 10 wt. %.
Examples of a demulsifier include, but are not limited to, anionic
surfactants alkyl-naphthalene sulfonates, alkyl benzene sulfonates
and the like), nonionic alkoxylated alkylphenol resins, polymers of
alkylene oxides (e.g., polyethylene oxide, polypropylene oxide,
block copolymers of ethylene oxide, propylene oxide and the like),
esters of oil soluble acids, polyoxyethylene sorbitan ester and the
like and combinations thereof. The amount of the demulsifier may
vary from about 0.01 wt. % to about 10 wt. %.
Examples of a corrosion inhibitor include, but are not limited to,
half esters or aril ides of dodecylsuccinic acid, phosphate esters,
thiophosphates, alkyl imidazolines, sarcosines and the like and
combinations thereof. The amount of the corrosion inhibitor may
vary from about 0.01 wt. % to about 0.5 wt. %.
Examples of an extreme pressure agent include, but are not limited
to, sulfurized animal or vegetable fats or oils, sulfurized animal
or vegetable fatty acid esters, fully or partially esterified
esters of trivalent or pentavalent acids of phosphorus, sulfurized
olefins, dihydrocarbyl polysulfides, sulfurized Diels-Alder
adducts, sulfurized dicyclopentadiene, sulfurized or cosulfurized
mixtures of fatty acid esters and monounsaturated olefins,
co-sulfurized blends of fatty acid, fatty acid ester and
alpha-olefin, functionally-substituted dihydrocarbyl polysulfides,
thia-aldehydes, thia-ketones, epithio compounds, sulfur-containing
acetal derivatives, co-sulfurized blends of terpene and acyclic
olefins, and polysulfide olefin products, amine salts of phosphoric
acid esters or thiophosphoric acid esters and the like and
combinations thereof. The amount of the extreme pressure agent may
vary from about (101 wt. % to about 5 wt. %.
Each of the foregoing, additives, when used, is used at a
functionally effective amount to impart the desired properties to
the lubricant. Thus, for example, if an additive is a friction
modifier, a functionally effective amount of this friction modifier
would be an amount sufficient to impart the desired friction
modifying, characteristics to the lubricant. Generally, the
concentration of each of these additives, when used, ranges from
about 0.001% to about 20% by weight, and in one embodiment about
0.01% to about 10% by weight based on the total weight of the
lubricating oil composition.
If desired, the sulfurized alkaline earth metal alkylphenate
detergent component (b) and/or the marine diesel engine lubricating
oil composition additives may be provided as an additive package or
concentrate in which the additives are incorporated into a
substantially inert, normally liquid organic diluent such as, for
example, mineral oil, naphtha, benzene, toluene or xylene to form
an additive concentrate. These concentrates usually contain from
about 20% to about 80% by weight of such diluent. Typically a
neutral oil having a viscosity of about 4 to about 8.5 cSt at
100.degree. C. and preferably about 4 to about 6 cSt at 100.degree.
C. will be used as the diluent, though synthetic oils, as well as
other organic liquids which are compatible with the additives and
finished lubricating oil can also be used. The additive package
will typically contain one or more of the various additives,
referred to above, in the desired amounts and ratios to facilitate
direct combination with the requisite amount of the oil of
lubricating viscosity.
The resulting marine diesel engine lubricating oil composition can
be used for applications associated with, for example, marine
cylinder lubricants, truck piston engine lubricants and the
like.
The following non-limiting examples are illustrative of the present
invention.
The tendency of marine lubricants to resist oxidation which can
lead to, for example, a decrease in Total Base Number during use,
can be evaluated using the Modified Institute of Petroleum 48
(MIP-48) Test.
Modified Institute of Petroleum 48 (MIP-48) Test
This test measures the degree of stability against oxidation-based
viscosity increase of the lubricant. The test consists of a thermal
and an oxidative part. During both parts of the test the test
samples are heated for a period of time. In the thermal part of the
test, nitrogen is passed through a heated oil sample for 24 hours
and in parallel during the oxidative part of the test, air is
passed through a heated oil sample for 24 hours. The two samples
were then cooled, and the viscosities of the samples were
determined. The BN depletion and viscosity increase of the test oil
caused by oxidation are determined and corrected for the thermal
effect. The oxidation-based viscosity increase for each marine
system oil composition was calculated by subtracting the kinematic
viscosity at 100.degree. C. of the nitrogen-blown sample from the
kinematic viscosity at 100.degree. C. for the air-blown sample, and
dividing the subtraction product by the kinematic viscosity at
100.degree. C. for the nitrogen blown sample.
TPP Content
The concentration of total free unsulfurized alkylhydroxyaromatic
compound and its unsulfurized metal salts (i.e., "total TPP" or
"total residual TPP") in detergent described hereinbelow was
determined by reverse phase High Performance Liquid Chromatography
(HPLC). In the HPLC method, samples were prepared for analysis by
weighing accurately 80 to 120 mg of sample into a 10 ml volumetric
flask, diluting to the level mark with methylene chloride, and
mixing until the sample is fully dissolved.
The HPLC system used in the HPLC method included a HPLC pump, a
thermostatted HPLC column compartment, HPLC fluorescence detector,
and PC-based chromatography data acquisition system. The particular
system described, is based on an Agilent 1200 HPLC with ChemStation
software. The HPLC column was a Phenomenex Luna C8(2) 150.times.4.6
mm 5 .mu.m 100 .ANG., P/N 00F4249E0.
The following system settings were used in performing the
analyses:
Pump flow=1.0 ml/min
Maximum pressure=200 bars
Fluorescence wavelength: 225 excitation 313 emission: Gain=9
Column Thermostat temperature=25 C
Injection Size=1 .mu.L of diluted sample
Elution type: Gradient, reverse phase
Gradient: 0-7 min 85/15 methanol/water switching to 100% methanol
linear gradient.
Run time: 17 minutes
The resulting chromatogram typically contains several peaks. Peaks
due to the free unsulfurized alkylhydroxyaromatic compound
typically elute together at early retention times; whereas peaks
due to sulfurized salts of alkylhydroxyaromatic compounds typically
elute at longer retention times. For purposes of quantitation, the
area of the single largest peak of the free unsulfurized
alkylhydroxyaromatic compound and its unsulfurized metal salt was,
measured, and then that area was used to determine the
concentration of the total free unsulfurized alkylhydroxyaromatic
compound and its unsulfurized metal salt species. The assumption is
that the speciation of alkylhydroxyaromatic compounds does not
change; if something does change the speciation of the
alkylhydroxyaromatic compounds, then recalibration is
necessary.
The area of the chosen peak is compared to a calibration curve to
arrive at the wt. % of free alkylphenol and free unsulfurized salts
of alkylphenols. The calibration curve was developed using the same
peak in the chromatogram obtained for the free unsulfurized
alkylhydroxyaromatic compound used to make the phenate product.
The following components are used below in formulating a marine
diesel engine lubricating oil composition.
ExxonMobil CORE.RTM. 600N: Group I-based lubricating oil was
ExxonMobil CORE.RTM. 600N basestock: available from ExxonMobil
(Irving, Tex.).
ExxonMobil CORE.RTM. 2500BS: Group I-based lubricating oil was
ExxonMobil CORE.RTM. 2500BS basestock, available from ExxonMobil
(Irving, Tex.).
Comparative Example A
Preparation of Basic Sulfurized Carbonated Calcium Alkyl
Phenate
A slurry of an alkylphenol wherein the alkyl radical was derived
from a polypropylene having an average of 12 carbon atoms, base
oil, fluorine-containing silicon foam inhibitor, and lime are added
to a reactor. The slurry was heated to 120.degree. C. and sulfonic
acid is added. Sulfur is slowly added to the reactor at about
130.degree. C., and at about 150.degree. C. decyl alcohol and
ethylene glycol were added slowly to the reactor which was kept at
about 150-155.degree. C. for the entire addition. The reaction
mixture was then heated to about 175.degree. C. and another aliquot
of ethylene glycol was added while simultaneously sparging
CO.sub.2. After carbonation, the mixture was heated to about
230.degree. C. and vacuum applied to remove water, ethylene glycol,
and decyl alcohol. Additional lube oil was blended in to achieve a
diluted detergent additive as characterized below in Table 1:
TABLE-US-00001 TABLE 1 TBN, mg KOH/g 263 Vis @ 100.degree. C. (cSt)
308 Ca (wt %) 9.63 S (wt %) 3.21 S/Ca 0.33
Example 1
Variant 1
Preparation of Basic Sulfurized Carbonated Calcium Alkyl
Phenate
(A) A non-overbased sulfurized alkylphenate detergent concentrate
is prepared using a process similar to that of Example 4 of U.S.
Pat. No. 5,529,705. The C.sub.12 alkylphenol of Comparative Example
A was reacted with lime and sulfur in the presence of a mixture of
formic and acetic acid promoter in the absence of a polyol promoter
at a temperature of between 260 and 410.degree. F. using a
programmed temperature and raw material addition profile. After
filtration to remove unreacted lime, an is then sparged into the
reaction mixture at a rate of about 2 to 2.5 Nm of air/hr/m.sup.3
of reaction product at 155.degree. C. for about 10 to 12 hours. The
final product is a non-overbased sulfurized alkylphenate detergent
concentrate substantially free of polyol promoter oxidation
products having a TBN of about 120 mg KOH/kg detergent, a calcium
content of about 4.25 wt. % and a sulfur content of about 5.5 wt. %
resulting in a sulfur to calcium ratio of 1.29.
(B) In a 2000 liter reactor, 699 kg of the reaction product of (A),
136 kg of lube oil 22.7 kg of alkyltoluene sulfonic acid (AS 305BD,
an alkylaryl sulfonic acid available from Chevron Oronite Company
LLC), 210 kg of isodecyl alcohol, 60 nil of antifoam, and 150 kg of
calcium hydroxide were first charged. After approximately 30
minutes of agitation to homogenize the mixture, the mixture was
heated to 149.degree. C. over 60 minutes. After reaching
149.degree. C., the temperature was increased further to
177.degree. C. over 60 minutes. During the ramp from 149.degree. C.
to 177.degree. C., 87 kg of ethylene glycol was charged at as rate
of 1.45 kg per hour such that glycol charging was completed when
the temperature reaches 177.degree. C.
Carbon dioxide was sparged into the reaction mixture at a rate of
0.14 kg per minute for a total of 30 minutes. At the same time, a
second glycol charge totaling 65.5 kg was metered into the reactor
over a period of 60 minutes. A second CO.sub.2 charge was started
immediately after completion of the first CO.sub.2 charge. The
second CO.sub.2 charge was 55 kg and was metered over a period of
175 minutes.
After completion of the carbonation step, the reactor temperature
was increased to 227.degree. C. as fast as possible while
simultaneously decreasing reactor pressure to 61) mm Hg or less.
The reactor was held at this temperature and pressure for 1 hour.
After 1 hour, the reactor contents were sparged with nitrogen for
additional hour at 227.degree. C. and approximately 50-100 mm Hg.
After completing the distillation step, the erode reaction mixture
was cooled to 150 to 170.degree. C. A filter aid was added and the
crude product was filtered to remove unreacted lime.
Variant 2
Variant 2 was prepared in substantially the same manner as variant
1 except air was sparged into the filtered product at 150 to
160.degree. C. for a period of 8 hours at atmospheric pressure. Au
rate was maintained at 5 standard liters per hour per kg of the
product.
Variant 3
Variant 3 was prepared in substantially the same manner as variant
1 except lime charge was increased to 164 kg.
Variant 4
Variant 4 was prepared in substantially the same manner as variant
3, except that the lime charge was increased to 164 kg and reaction
product was subjected to the air sparging step described in variant
2.
Variant 5
Variant 5 was prepared as follows: 223 kg, of the product of
Example 1A, 18 g foam inhibitor, 66.8 kg 2-ethylhexanol and 24.5 kg
130N base oil were loaded in a 750 L stainless steel reactor at
65.degree. C. Next, 7.3 kg AS 305BD was added to the mixture at
65.degree. C. Then, 43.5 kg hydrated lime was added in the reactor
under vigorous agitation. The reactor temperature was increased
from 65.degree. C. to 149.degree. C. in 50 min and the pressure was
set to 0.95 bar abs. The reactor mixture was warmed up to
170.degree. C. in 1 hour and during the same period, 27.8 kg
ethylene glycol was added. Then, 1.4 kg CO.sub.2 was added in 30
min and 20.9 kg ethylene glycol in 1 hour.
At the end of the CO.sub.2 charge addition, a second CO.sub.2
charge of 17.7 kg was added during 2 hours. The reactor pressure
was then set to 1 bar abs to allow reactor sampling. The reactor
was then put under vacuum (30 mbar) in 1 h at 170.degree. C., and
the temperature was increased to 225.degree. C. in 50 mitt and both
conditions (225.degree. C./30 mbar) were maintained for 1 h for
solvent distillation. The product was cooled down to 170.degree. C.
and filtered with Primisil filter aid at 160.degree. C. The
filtered product was span-zed with air (22.6 Orlin) at 160.degree.
C. during 8 h under mild agitation.
Variant 6
Variant 6 was prepared in substantially the same manner as variants
1-5 except the synthesis was conducted in a 4 liter glass reactor
and the sulfur charge was reduced during the preparation of
reaction product (A) to lower the sulfur to calcium ratio. 1000
grams of the reaction product of (A) with a sulfur to calcium ratio
of 1.13, 110 grams of lube oil, 300 grams of isodecyl alcohol, 195
grams of lime, and 32 grams of alkyltoluene sulfonic acid were
charged to the laboratory reactor. The reaction mixture was then
heated as fast as possible to 149.degree. C. After reaching
149.degree. C., the reactor temperature was then ramped to
177.degree. C. over 1 hour while simultaneously adding 125 grams of
glycol. The glycol was also charged over 1 hour.
After reaching 177.degree. C., 6 grams of CO.sub.2 was sparged into
the reaction mixture over a period of 30 minutes after which an
additional 79 grams of CO.sub.2 was charged over a 2 hour period.
Following the carbonation step, the reactor temperature was
increased to 218.degree. C. while simultaneously reducing the
pressure to 40 mm Hg. The reactor was held at the final
distillation conditions (218.degree. C. and 40 mm Hg) for 30
minutes. Products were then filtered after the addition of some
filter aid. The filtered products were then heat soaked in the same
4 liter reactor for 24 hours at 225.degree. C. with a small
nitrogen sweep into the head space above the liquid layer. Oil was
then added to adjust calcium to approximately 9.5 wt %.
Variant 7
Variant 7 was also prepared in a laboratory reactor using the
charges and procedure described for variant 6. Variant 7, however,
used the reaction product of (A) instead of a reaction product of
(A) with a substantially lower sulfur to calcium ratio.
The analytical results for variant 1-7 are set forth below in Table
2:
TABLE-US-00002 TABLE 2 Variant 1 2 3 4 5 6 7 Ca 9.8 9.76 10 10 10.1
9.2 9.6 (wt %) Vis @ 437 486 439 443 951 201 374 100.degree. C.
(cSt) TPP 1.19 1.21 1.27 1.3 1.53 1.39 1.01 (wt %)
Comparative Example B and Examples 1a-1e
The following marine diesel engine lubricating oil compositions
were prepared using components and amounts as set forth below in
Table 3. The additive components and amounts were the same for each
of the examples. The TBN of these compositions was maintained at
38.7 to 40.1 mgKOH/g, and the finished oil viscosity was maintained
at 19.4 to 20.5 cSt at 100.degree. C. regardless of which overbased
detergent was used for the test composition. The marine diesel
engine lubricating oil compositions were evaluated using the MIP-48
test.
TABLE-US-00003 TABLE 3 Comp. Component Type Units Ex. B Ex. 1a Ex.
1b Ex. 1c Ex. 1d Ex. 1e Comp. Ex. A [m %] 14.89 -- -- -- -- --
Example 1, variant 1 [m %] -- 14.19 -- -- -- -- Example 1, variant
2 [m %] -- -- 14.01 -- -- -- Example 1, variant 3 [m %] -- -- --
13.87 -- -- Example 1, variant 4 [m %] -- -- -- -- 13.99 -- Example
1, variant 5 [m %] -- -- -- -- -- 13.79 Dispersant [m %] 1.08 1.08
1.08 1.08 1.08 1.08 Foam inhibitor [m %] 0.10 0.10 0.10 0.10 0.10
0.10 ExxonMobil CORE .RTM. [m %] 53.09 52.87 52.81 52.77 52.81
52.74 600N ExxonMobil CORE .RTM. [m %] 30.84 31.76 32.00 32.18
32.02 32.29 2500BS Total Amount [m %] 100.00 100.00 100.00 100.00
100.00 100.00 TBN [mgKOH/g] 40.1 39.7 39.3 39.8 40.1 38.7 Viscosity
(at 100.degree. C.) [cSt] 19.42 19.86 19.89 19.99 19.96 20.51
MIP-48 Test Result, [%] 46.7 29.8 29.1 22.5 23.5 29.7 Viscosity
Increase
Comparative Example C and Examples 2a-2e
The following marine diesel engine lubricating oil compositions
were prepared using components and amounts as set forth below in
Table 4. The additive components and amounts were the same for each
of the examples. The TBN of these compositions was maintained at
30.2 to 30.5 mgKOH/g and the finished oil viscosity was maintained
at 14.0 to 14.2 cSt at 100.degree. C. regardless of which overbased
detergent was used for the test composition. The marine diesel
engine lubricating oil compositions were evaluated using the MIP-48
test.
TABLE-US-00004 TABLE 4 Comp. Components Units Ex. C Ex. 2a Ex. 2b
Ex. 2c Ex. 2d Ex. 2e Comp. Ex. A [m %] 3.64 -- -- -- -- -- Example
1, variant 1 [m %] -- 3.47 -- -- -- -- Example 1, variant 2 [m %]
-- -- 3.42 -- -- -- Example 1, variant 3 [m %] -- -- -- 3.39 -- --
Example 1, variant 4 [m %] -- -- -- -- 3.42 -- Example 1, variant 5
[m %] -- -- -- -- -- 3.37 Other Additives Detergent(s) [m %] 8.36
8.36 8.36 8.36 8.36 8.36 Antiwear Agent [m %] 0.52 0.52 0.52 0.52
0.52 0.52 Foam Inhibitor [m %] 0.03 0.03 0.03 0.03 0.03 0.03
ExxonMobil CORE .RTM. [m %] 84.15 84.10 84.08 84.07 84.08 84.07
600N ExxonMobil CORE .RTM. [m %] 3.30 3.52 3.59 3.63 3.59 3.65
2500BS Total Amount [m %] 100.00 100.00 100.00 100.00 100.00 100.00
TBN [mgKOH/g] 30.4 30.5 30.4 30.5 30.3 30.2 Viscosity (at
100.degree. C.) [cSt] 14.01 14.06 14.00 14.06 14.06 14.17 MIP-48
Test Result, [%] 25.3 20.1 15.6 16.0 17.7 16.1 Viscosity
Increase
Comparative Example D and Examples 3a-3e
The following marine diesel engine lubricating oil compositions
were prepared using same components and amounts as set forth below
in Table 5. The additive components and amounts were the same for
each of the examples. The TBN of these compositions was maintained
at 69.6 to 70.5 mg KOH/g and the finished oil viscosity was
maintained at 20.0 to 20.6 cSt at 300.degree. C. regardless of
which overbased detergent was used for the test composition. The
marine diesel engine lubricating oil compositions were evaluated
using the MIP-48 test.
TABLE-US-00005 TABLE 5 Comp. Components Units Ex. D Ex. 3a Ex. 3b
Ex. 3c Ex. 3d Ex. 3e Comp. Ex. A [m %] 9.30 -- -- -- -- -- Example
1, variant 1 [m %] -- 8.86 -- -- -- -- Example 1, variant 2 [m %]
-- -- 8.75 -- -- -- Example 1, variant 3 [m %] -- -- -- 8.66 -- --
Example 1, variant 4 [m %] -- -- -- -- 8.74 -- Example 1, variant 5
[m %] -- -- -- -- -- 8.61 Other Additives Detergent(s) [m %] 10.74
10.74 10.74 10.74 10.74 10.74 Dispersant [m %] 1.50 1.50 1.50 1.50
1.50 1.50 Foam inhibitor [m %] 0.04 0.04 0.04 0.04 0.04 0.04
ExxonMobil CORE .RTM. [m %] 54.49 54.35 54.31 54.28 54.31 54.27
600N ExxonMobil CORE .RTM. [m %] 23.93 24.51 24.66 24.78 24.67
24.84 2500BS Total Amount [m %] 100.00 100.00 100.00 100.00 100.00
100.00 TBN [mgKOH/g] 70.2 70.5 69.8 70.4 70.2 69.6 Viscosity (at
100.degree. C.) [cSt] 20.00 20.08 20.05 20.09 20.15 20.60 MIP-48
Test Result, [%] 38.1 22.8 24.2 27.6 21.9 19.6 Viscosity
Increase
Comparative Example E and Examples 4a-4-b
The following marine diesel engine lubricating oil compositions
were prepared using, components and amounts as set forth below in
Table 6. The additive components and amounts were the same for each
of the examples. The TBN of these compositions was maintained at
68.4 to 68.9 mg KOH/g and the finished oil viscosity was maintained
at 19.9 to 20.2 cSt at 100.degree. C. regardless of which overbased
detergent was used for the test composition. The marine diesel
engine lubricating, oil compositions were evaluated using the
MIP-48 test.
TABLE-US-00006 TABLE 6 Comp. Components Units Ex. D Ex. 4a Ex. 4b
Comp. Ex. A [m %] 9.30 -- -- Example 1, variant 6 [m %] -- 9.40 --
Example 1, variant 7 [m %] -- -- 9.20 Other Additives Detergent(s)
[m %] 10.70 10.70 10.70 Dispersant [m %] 1.50 1.50 1.50 Foam
inhibitor [m %] 0.04 0.04 0.04 ExxonMobil CORE .RTM. [m %] 54.48
54.51 54.45 600N ExxonMobil CORE .RTM. [m %] 23.98 23.85 24.11
2500BS Total Amount [m %] 100.00 100.00 100.00 TBN [mgKOH/g] 68.6
68.4 68.9 Viscosity (at 100.degree. C.) [cSt] 20.03 19.90 20.24
MIP-48 Test Result, [%] 26.5 12.8 10.4 Viscosity Increase
Comparative Example E-J
The following marine diesel engine lubricating oil compositions
were prepared using the same components and amounts as set forth
below in Table 7. The additive components and amounts were the same
for each of the examples. The TBN of these compositions was
maintained at 9.3 to 9.5 mg KOH/g and the finished oil viscosity
was maintained at 14.39 to 14.48 cSt at 100.degree. C. regardless
of which overbased detergent was used for the test composition. The
marine diesel engine lubricating oil compositions were evaluated
using the MIP-48 test.
TABLE-US-00007 TABLE 7 Comp. Comp. Comp. Comp. Comp. Comp.
Components Units Ex. E Ex. F Ex. G Ex. H Ex. I Ex. J Comp. Ex. A [m
%] 1.74 -- -- -- -- -- Example 1, variant 1 [m %] -- 1.66 -- -- --
-- Example 1, variant 2 [m %] -- -- 1.64 -- -- -- Example 1,
variant 3 [m %] -- -- -- 1.62 -- -- Example 1, variant 4 [m %] --
-- -- -- 1.63 -- Example 1, variant 5 [m %] -- -- -- -- -- 1.61
Other Additives Detergent(s) [m %] 2.13 2.13 2.13 2.13 2.13 2.13
Dispersant [m %] 0.87 0.87 0.87 0.87 0.87 0.87 Foam inhibitor [m %]
0.03 0.03 0.03 0.03 0.03 0.03 ExxonMobil CORE .RTM. [m %] 80.66
80.63 80.63 80.62 80.62 80.62 600N ExxonMobil CORE .RTM. [m %]
14.57 14.68 14.70 14.73 14.72 14.74 2500BS Total Amount [m %]
100.00 100.00 100.00 100.00 100.00 100.00 TBN [mgKOH/g] 9.5 9.3 9.4
9.3 9.3 9.3 Viscosity (at 100.degree. C.) [cSt] 14.39 14.43 14.44
14.45 14.46 14.48 MIP-48 Test Result, [%] 57.1 61.5 56.6 60.7 58.2
58.2 Viscosity Increase
It will be understood that various modifications may be made to the
embodiments disclosed herein. Therefore the above description
should not be construed as limiting, but merely as exemplifications
of preferred embodiments. For example, the functions described
above and implemented as the best mode for operating the present
invention are for illustration purposes only. Other arrangements
and methods may be implemented by those skilled in the art without
departing from the scope and spirit of this invention. Moreover,
those skilled in the art will envision other modifications within
the scope and spirit of the claims appended hereto.
* * * * *